Reduced-order state observer for MIMO nonlinear systems (Q2705635)

The authors consider the following MIMO nonlinear system: NEWLINE\[NEWLINE \dot{x}=f(x,t)+\sum_{i=1}^{m} g_{i}(x,t)u_{i}(t), \qquad y=h(x,t).NEWLINE\]NEWLINE A reduced-order observer is constructed. Furthermore, they prove that the observer has the characteristic of exponential convergence and that the convergence speed of the observer is adjustable. A simulation example is presented to illustrate that their approach is effective.